The instant invention is directed generally to optical readout displays for electronic watches or clocks, and specifically to displays having electrically energized optical elements located at the numbered, or hour, positions on the watch or clock face.
Most currently available electronic watches and clocks use decimal digit displays to show the time and other information. Decimal digit displays show the time accurately and make it easier for children to learn to tell the time. In addition to telling time, however, traditional watches also serve as items of personal adornment and manufacturers have devoted much effort to appearance and styling. Digital displays severly restrict the variations in style and appearance which are important for an item of jewelry. Another drawback of digital displays is the size required for the watches using them. Present watches are bulky for men and far too large to appeal to most women.
Several U.S. patents disclose other types of electrically energized optical displays to show the time for electronic watches. Toshio Kashio and Leo Wiesner show sets of electrically energized optical elements to present hour and minute hand positions in U.S. Pat. Nos. 3,844,105 and 3,908,355 respectively. U.S. Pat. Nos. 3,754,392; 3,919,935; and 3,922,847 to R. Gary Daniels, Toshio Kashio, and co-inventors Bobby Gene Culley and Engelbert Wolfgang Kehren respectively use two concentric rings of 12 and 60 optical elements to show hour and minute positions.
These displays use less power than decimal digit displays as only two elements need be energized to show the time. The large number of optical elements required, however, adds to the bulk and cost. If the optical elements are LCDs, the large number is especially disadvantageous since an equal number of connections must be made to the chip thus adding further to bulk and cost. The tightly packed ring of 60 optical elements also restricts the appearance and styling variations possible.
The instant invention provides time displays for electronic watches and clocks which use a much smaller number of optical display elements than prior art displays. The smaller number of elements opens up new styling possibilities and reduces size and cost for watches. The time and space code used to present the necessary information on the fewer elements also adds a visually pleasing animation. The new styling possibilities and the added animation will permit designers to make electronic watches more competitive in appearance and individuality with mechanical watches which have a long tradition as items of personal jewelry. The styling along with the smaller size will especially appeal to women and at least double the potential market for electronic watches. Animation further adds to the general appeal and lower cost is obviously important for the mass market.
The instant invention provides effective time displays with fewer optical display elements by combining conventional methods of time presentation with special time and space codes. When using 12 optical display elements located at the traditional numbered, or hour, positions on the watch or clock face, the invention shows the hour and 5 minute positions directly by energizing an element for each and distinguishing them by a time code. The time presentation is completed by further energizing the 12 elements in a combination time and space code to show the number of minutes from the 5 minute position. The invention further adds time or space coding for hour and 5 minute indications to display the time on less than 12 elements, such as six or four.
With 12 element displays, the 5 minute indication can be on steadily while the hour indication pulses alternately with the minute indications. The minute indications appear as animated arrows flashing from the 5 minute position in the intervals between hour pulses. The length of the arrow shows the number of minutes and the clockwise or counter clockwise direction shows before or after. Alternatively the minute indications can be limited to minutes after shown by clockwise movement. Or 5 minute and hour indications can remain on continuously with the 5 minute indication flickering to distinguish them. The minute indications then consist of apparent clockwise or counter clockwise rotations to show the minutes after or before respectively. The apparent rotations for minute indications stand out clearly from the hour and 5 minute indications.
The invention reduces the number of optical elements from 12 to six by alternating the hour and 5 minute indications and energizing two adjacent elements to indicate the intermediate positions. Minute indications accompany the 5 minute indications. The invention makes a further reduction to only four optical elements for the time display by again alternating the hour and 5 minute indications and using a time and space code for the positions adjacent to the quarterly positions. The quarterly positions are indicated individually by the four optical elements and the adjacent positions by flashing a one element arrow forward or back of the quarterly position. A demand switch obtains minute and second indications alternately in place of the hour and 5 minute indications. Each element can indicate the number of minutes past or apparent rotations can again indicate minutes before or after.
Various other types of time and space coding can be used for time presentations according to the invention. Information other than time information, such as alarm settings and calendar register days and months can also be shown in a similar way on the same displays. Seconds information can be shown in the same way as a minute information, on demand, or in a regular sequence. Seconds can also be shown along with hours and minutes by a combination of displays such as one having 12 elements for hours and minutes with one having four elements for 5 seconds or seconds. Finally, sequences such as repeated rotations or periodic flashing of all elements can serve as visual alarm or alert signals.
The time displays of the instant invention can use LEDs or LCDs as the optical elements in watches, and other types of optical elements in clocks and other suitable time keeping devices. It is expected that the displays will also be able to use other elements which may become practical in the future. As only two elements need be energized at a time, according to the invention the time displays use less power than decimal digit displays, making smaller batteries feasible for further reduction in the size of the watch. The power saving will be greater when LEDs are used. Since LCDs require connections from the chip to each element, reduction in the number of elements when LCDs are used is especially important for reduction in the cost of the watch.
While the previous discussion has been concerned with electronic watches, it will be recognized that the time displays of the instant invention can be used for electronic clocks. Relatively minor modifications to the circuitry of the invention adapt it for operation from a 60 hertz timing source, that is generally used for clocks in this country, or for operation from other frequency timing sources. Where power is not a problem, larger and brighter display elements may be used simply by providing drivers to handle the necessary level of power.